In Gloucester last week I fell into conversation with an elder from a local mosque who was touring the West Country talking to Muslim communities. He was doing so, he explained, because the congregation in his mosque felt they had to address the “lies and propaganda” – his words, not mine – coming from extremist Islamist groups active in this country. This was, he felt, both corrupting the younger generation’s understanding of Islam and encouraging them to radicalisation. It was, he said, his duty as a Muslim to redress this.

My travelling friend would have welcomed the announcement yesterday that Sara Khan is to be the new Commissioner for Countering Extremism. Ms Khan has a record of helping...